Make sure users get the idea that clutter_init()
has a return value that needs to be checked.
These were fixed via sed magic:
sed -i -s -e "s/clutter_init (.*)/\
if (& != CLUTTER_INIT_SUCCESS)\n return 1/"\
doc/*/*/*.{c,xml} doc/*/*.xml
http://bugzilla.clutter-project.org/show_bug.cgi?id=2574
